2. Since ancient times, fish have been held in a wide variety of man-
made structures.
These structures were built using simple methods and readily
available materials.
The fish or other aquatic crop were cared for by the fish farmer and
relied upon as an important source of protein for their families.
Typical fish farm was developed by forming small ponds by hand,
or an even simpler method of trapping tidal water flow in estuaries by
building simple water retaining structures.
INTRODUCTION
4. Open space for aeration
Future expansion of the project
susceptibility of the site to flooding
availability of suitable manpower to operate the farm
proximity of markets
ability to secure the site against poaching and sabotage
potential impact on neighbours and environment.
In general, knowledge of local geography and local and
regional hydrology, geology, climate and weather
5. Extensive Earthen pond Built to farm fish, specific and
shape; water level and water
quality monitored and
maintained; some
supplementary feeding;
predator control.
Intensive Tanks,
raceways,
troughs,
cages, small
earthen ponds
Complete feeding. Generally,
prepared feeds; highly
managed ponds with regular
water exchange/management
Extensive and Intensive Systems
6. Design of earthen ponds
Earthen ponds comprise the major capital investment in
aquaculture facilities throughout the world.
More than 90 per cent of the total global production is from
ponds.
The ponds and buildings should be laid out for efficient and
economic operation and the best utilization of the land.
Construction of ponds and drainage systems should be
planned and supervised by both an aquaculturist and an
engineer, particularly if a large system is to be constructed.
8. Type and Shape
There are three basic structural types.
excavated pond in which earth is removed and used for building the
banks. This type of pond can be constructed on flat or undulating land.
Levee ponds are constructed on very flat land and are similar in structure
to rice bays except that the banks must be high enough to contain the
necessary depth of water.
Gully or ravine ponds are restricted to hilly country and are constructed
by damming valleys or gullies.
Ponds should be square or rectangular to make the most efficient use of
available land. It is more economical to construct square ponds;
however, rectangular ponds are easier to manage.
10. Buildings and equipment
1.office
2.toilet and washroom
3.aboratory
4.meal room
5.general workroom with tanks for holding, sorting, quarantining and
treating fish, with vehicular access
plant room with filters and airblowers
store rooms for chemicals, feed, equipment
garages for vehicles, boats, pumps, traps, nets, mowers
workshop for repairing and making equipment
handling and packaging room for preparing fish for packaging and
dispatch
12. Supply and drainage
inlet and outlet. Both should be screened; the inlet to prevent the entry of
trash fish and other undesirable aquatic fauna, and the outlet to prevent the
loss of stocked fish.
Construct ponds so that they can be drained individually, completely and
rapidly.
This will enable the removal of all fish during harvesting and facilitate
efficient management, particularly when water quality and disease problems
occur.Each pond should have a deep (at least 2 metres) and a shallow (1-
metre) section; however, the preferred depth varies with the species and the
locality. (Buffer)
13. Build banks with slopes of about 3: 1. Line the banks with
topsoil and plant with grasses to ensure stability and prevent
erosion.
There is a large variation in the size of earthen ponds used in
aquaculture throughout the world and authorities disagree on
the optimum size of ponds.
14. The success of any production system in industry and agriculture
relies heavily on design and construction.
A well designed and constructed system provides the foundation for
successful operations.
Even the best management techniques can do little to optimize
production in poorly designed and inadequately constructed systems.
This applies to ponds at all levels of management.
CONCLUSION